Not applicable.
Not applicable.
Numerous medical procedures involve the insertion of intravenous devices into patients with varying medical conditions. Among these medical conditions are a number of diseases that also present a risk of infection to the medical practitioner providing care. The insertion of intravenous devices generally requires the use of a sharp implement, which conventionally has been a hollow bore needle, for piercing the skin to allow insertion of a hollow catheter. The distal end of the catheter must be inserted into, but not through, a blood vessel. Normally, proper placement of the catheter is confirmed by visual observation of a xe2x80x9cflash-backxe2x80x9d of blood that passes through the hollow needle into a stationary flash chamber located at the proximal end of the catheter assembly, where it is visualized. Once the catheter has been inserted to the proper position within the blood vessel, the sharp implement needs to be withdrawn and properly discarded. The acts of withdrawal and disposal pose the greatest threat to the health of the practitioner, since the implement remains sharp enough to pierce skin and is potentially carrying an infectious agent. With the prior art designs, the hollow needle and flash chamber contain a rather large amount of potentially infectious blood, with the result that inadvertent skin puncture of the practitioner can lead to significant transference of infectious agent from the patient to the practioner.
A system for providing protection from the risk of infection during withdrawal and disposal of a piercing instrument must accommodate various operational constraints. A primary constraint is to minimize interference with the execution of the medical procedure prior to withdrawal and disposal. Accordingly, the system should minimize or eliminate additional steps and preferably should not significantly alter the steps performed without the system. Medical care often occurs in stressful and hurried situations and hence, ease of use is a second constraint. Preferably, the system should not compel the practitioner to carry out any but the most minimal actions to accomplish safe withdrawal and disposal. Additional constraints include cost and ease of construction, compatibility with existing equipment, and adaptability of use across variations in patients and insertion locations.
A very desirable benefit of such systems would be reduction in the risk of accidental infection. Risk of infection can be reduced by, inter alia, automatic operation, encapsulation of the piercing implement, and a reduction in the fluid and tissue volume associated with piercing instrument removalxe2x80x94since greater volume potentially increases the amount of the infectious agent present. Risk can also be reduced by quick operation. If the system is effective simultaneously with, or at least immediately subsequent to withdrawal, exposure of the piercing instrument is minimized, as is the risk of accidental infection.
Numerous approaches to providing a safer withdrawal and disposal system have been employed, though two general categories of systems predominate. One category of system deploys a secondary sheath between a needle and a catheter to envelope the needle upon withdrawal from the piercing site, prior to complete withdrawal of the secondary sheath and needle from the catheter. This category of system is relatively sizable and complex, yet still poses a risk of reemergence of the needle. Preventing reemergence may necessitate even more apparatus. Withdrawal is also generally associated with emission of a significant amount of body fluid with this category of system, among other adverse consequences. The second category of system involves affixing a point guard about the tip of the piercing instrument after withdrawal. This approach often requires substantial complexity and substantial additional actions to implement. What""s more, with this second category of system, better execution of one desirable benefit, such as secure encapsulation of a piercing instrument, is often exchanged for a poorer execution of another desirable benefit, such as automatic operation.
As mentioned above, most prior approaches utilize a hollow needle (in fluid communication with a stationary flash chamber having a relatively large volume) for piercing. Hollow needle and flash chamber assemblies, however, present a risk of exposure to the body fluids they contain when the needle is withdrawn. In fact, research reveals that the risk of infection from a hollow needle is many times greater than that from a solid needle. This difference probably arises from the large reservoir of blood within the hollow needle and flash chamber assembly, that then becomes the source of inoculation when inadvertent needle stick injuries occur. Solid needles, on the other hand, have no such reservoir for inoculation. Moreover, when using a hollow needle with a catheter the user may receive an incorrect xe2x80x9cflashbackxe2x80x9d signal. The xe2x80x9cflashbackxe2x80x9d signal is the entry, or xe2x80x9cflashingxe2x80x9d, of blood into a viewing chamber (called the flashback chamber) in the interior of the catheter and needle system. The flash occurs when a blood vessel is entered and blood can flow into the catheter interior. Hollow needles allow blood to flow into the catheter interior even if only the needle, but not the catheter, has entered the blood vessel. Hence, the user must guess to what degree it is necessary to further insert the needle and catheter, after observing the flashback, to ensure that the catheter is correctly inserted. A system providing greater certainty of correct catheter insertion is preferable.
The objectives of the present invention include:
The provision of an improved piercing system which entails a minimum of hindrance to the optimum execution of a medical procedure.
The provision of an improved piercing system that requires minimum additional actions following the execution of a medical procedure such as the insertion of a catheter.
The provision of an improved piercing system that requires minimal alterations of the actions involved in the execution of a medical procedure such as the insertion of a catheter.
The provision of an improved piercing system with ease of use sufficient to curtail any additional demands on the medical practitioner""s attention.
The provision of an improved piercing system that requires minimal additional actions by the medical practitioner to realize the improvement in safety.
The provision of an improved system and method for catheter insertion using a solid needle to reduce the possibility of infection transference.
The provision of an improved piercing system that is relatively inexpensive.
The provision of an improved piercing system of simplified construction.
The provision of an improved piercing system compatible with existing medical equipment.
The provision of an improved piercing system adaptable for use across variations in patients and piercing locations.
The provision of an improved piercing system that reduces the risk of accidental infection.
The provision of an improved piercing system that operates automatically.
The provision of an improved piercing system that completely encloses the penetrating elements of the piercing instrument.
The provision of an improved piercing system that reduces the amount of fluids and tissue which accompany withdrawal of the piercing instrument.
The provision of an improved piercing system that occurs sufficiently fast to be in effect simultaneously with or at least immediately after withdrawal of the piercing instrument.
The provision of an improved piercing system, comprised of a catheter and needle, that gives visual confirmation only when the catheter is correctly inserted, and not when just the needle is correctly inserted.